Development of photographic film by the "wet" process exposes the film to a series of chemicals in either a continuous or batch process. In batch processing, film or paper is loaded into a single drum, and a sequence of chemicals is added and removed from the drum to effect development of the film. Proper development requires precise control of the concentration of the chemicals, temperature of the chemicals, and the time the film is exposed to the chemicals. Typically these chemicals are supplied in concentrated form as single or multiple concentrates and are diluted to the proper concentration for use in the developing process.
Each process of film development requires different concentrations. Making such a large array of chemicals ahead of time creates a problem in that the shelf-life of these chemicals is decreased once they are in diluted form. As a result, there is a reasonable chance that some chemicals may remain unused for a long period of time, exceed their shelf life, and thus be wasted. In addition, preparation of these chemicals by hand is undesirable as it exposes the operator to unnecessary potential contact with the chemicals.
It is therefore highly desirable to provide a device that is capable of mixing a diverse variety of chemicals on an as-needed basis. It is further desirable to provide an apparatus that performs this function automatically without the need for manual dilution and preparation of the chemicals.